wallthickness = 3
boxlength = 260
boxwidth = 120
boxheight = 3

outside = Box lengthsegs:1 widthsegs:1 heightsegs:1 length:boxlength width:boxwidth height:boxheight mapcoords:on pos:[0,0,0] isSelected:on
inside = Box lengthsegs:1 widthsegs:1 heightsegs:1 length:(boxlength - (2*wallthickness)) width:(boxwidth - (2*wallthickness)) height:(3* boxheight) mapcoords:on pos:[0,0,(-1*boxheight)] isSelected:on

select outside
ProBoolean.CreateBooleanObject outside inside 2 0 1
	